Blower wheel



April 3, 1934. p, E GOOD 1,953,297

BLOWER WHEEL Filed Marh 22, 1930 ill/IA i Patented Apr. 3, 1934 PATENToFFic BLOWER WHEEL Paul E. Good, Riverton, N. J., assignor to ElliottCompany, Pittsburgh, Pa., a corporation of Pennsylvania ApplicationMarch 22,

5 Claims.

This invention relates to means for securing a rotor to a shaft in suchfashion that the rotor may be readily removed from the shaft. One objectof my invention is to provide an improved mounting for a rotor, wherebythe same may be securely mounted on a shaft and yet readily removed whendesired. A further object of my invention is to improve the constructionof the mounting for a rotor on a shaft, this improved constructionpermitting the removal of the rotor with facility from the shaft.Further objects of my invention will appear inthe course of the ensuingdescription, and will be more clearly pointed out in the claims.

For purposes of illustration, I have illustrated my invention asembodied in a blower wheel forming a part of a centrifugal blowerconstruction; and accordingly, in the drawing,

Figure 1 is a longitudinal sectional view taken through one end of ashaft and through a blower wheel mounted thereon, the section beingtaken on line I-I of Figure 3;

Figure 2 is a transverse section on the line II-II of Figure 1;

Figure 3 is an end elevation of the mechanism shown in Figure 1;

Figure 4 is an end view similar to Figure 3, but

with the securing nut removed and replaced by a removing device;

Figure 5'is a view similar to Figure 1,\but on a reduced scale, with analternative device in position for removing the blower wheel from theshaft; and

Figure 6 is a view similar to Figure l, with a modied device in positionfor removing the blower wheel from the shaft.

My invention is broadly applicable to various types of rotors which aremounted on shafts in such fashion as to prevent relative rotationbetween the two. Diiiiculty is often encountered in removing the rotorwhen repairs, or some necessity for taking the machine apart requiresthat the rotor be slid off the shaft. My invention is particularlyuseful in connection with avblower wheel forming part of a centrifugalblower. Furthermore, if the blower wheel be cast of aluminum alloy orother metal which has a relatively low structural strength it isobviously not desirable to drill holes in the wheel for the attachmentof devices which may be used as anchors in drawing the wheel from theshaft. In other Words, it is undesirable t-o in any way decrease thestrength of the hub of the blower wheel. Another 'difficulty encounteredin removing a blower wheel may result from the construction 1930, SerialNo. 438,067 (ci. 287-53) of the centrifugal blower itself, in that theshaft on which the blower wheel is mounted may project through an-opening in a solid casting, making it impossible to use hammers frombehind the wheel to force the same oif the shaft. In my improvedmounting for a rotor, the parts are so assembled that the blower wheelmay be readily removed from its shaft when desired.

In the illustrative embodiment shown herein,

the rotor consists of a blower wheel 7, the form and shape of this wheelbeing unimportant and, therefore, not shown. The blower wheel 7surrounds and 'is mounted on a reduced portion 10 of a shaft 8, ashoulder 9 being accordingly formed between the reduced portion 10 andthe main body -of the shaft 8. The portion l0 is somewhat tapered sothat the diameter of the' shaft gradually decreases from the shoulder 9toward the end of the portion 10.

Between the wheel 7 and the reduced shaft portion 10 is a taperedbushing or sleeve 1l whose bore is'proportioned to nt the reducedportion 10 of the shaft 8. The outside of the bushing 11 issubstantially cylindrical, and fits the cylindrical bore 12 in theblower wheel 7. The bushing 11 therefore serves as wedging means totighten the rotor 7 on its shaft. This friction between the bushing, therotor, and the shaft portion l0 would, with ordinary loads, besulficient to prevent slipping of the rotor. If desired, however,additional security against slippage may easily be afforded. In suchcase, a keyway 13 may soA be cut in both the shaft portion 10 and the fwheel 7, the sleeve 1l being slotted throughout its entire length tocomplete the opening for a key 14, which, when inserted in position,prevents relatively rotation between the shaft 8 and blower wheel 7.

The outer end 16 ofthe shaft portion 10 is still further reduced indiameter, and is threaded. to receive a nut 17 having an inwardlydirected peripheral fiange 18. This flange surrounds the outer end ofthe sleeve 11; and in order to force the blower wheel 7 into positionagainst the shoulder 9, the nut 17 may be screwed inwardly on thethreaded portion 16. A hardened washer 20 may be interposed between thefiange 18 and the hub of the blower wheel 7. The outer end of the hub ofthe blower wheel 7 is formed with a machined surface'Zl which isengageable by the hardened washer 20, when, as above described, the nut17 is tightened. As is shown in Figures 1 and 3, one or more set screws22 are arranged within the nut 17, the set screws projecting inwardlyand bearing against the outer end of the sleeve 11. These set screws actas locking means to prevent relative rotation between the nut 17 and theshaft portion 10. A cotter pin 15 may additionally be passed through thenut 17 and shaft portion 10 for the same purpose (see Figure 3). A

In Figure 4 is shown a device which may be employed for removing thewheel 7 from the shaft 8. To use this device, the nut 17 is firstremoved.

Y As shown in Figure 4, this device takes the form of an acorn nut 23which is adapted to cooperate with screw threads 24 on the outer end ofthe sleeve 11.

In Figure 5 is shown an alternative device which may be employed forremoving the wheel 7 from the shaft 8. The nut 17 having first beenremoved, a nut 26 formed with threads for cooperating with the threads24 on the sleeve 11 is screwed onto the sleeve; and by bringing this nut26 to bear on the surface 21 of the hub of the rotor 7, the sleeve 11 iswithdrawn.

In Figure 6 is shown another modication of a device which may beVemployed for removing the wheel 7 from the shaft 8. Similarly, as inthe form shown in Figure 4, a device 27 replaces the nut 17, except thatit is provided with threads 28 adaptedto engage the screw threads 24 onthe sleeve l1 instead of the screw threads on the outer end 16 of theshaft. A cap screw 30V eX- tends inwardly through the device 27 toengage the outer end portion 16, this cap screw being adjustable in anobvious manner.

Two methods of assembling the rotor and shaft may be employed. In thefirst method, the sleeve 11 is rst assembled in the bore of the huhofthe blower, wheel 7. It will be noted that the sleeve is tapered, sothat the blower wheel and sleeve may be slipped onto the shaft portion10, the sleeve sliding on the shaft portion 10 without substantialfrictional resistance until the hub approaches fairly close to theshoulder 9. The washer 20 is temporarily omitted; andthe nut 17 isemployed for forcing the sleeve 11 and Wheel 7 into position as 'showninFigure 1. It should be noted in this connection that the nut 17 has asubstantial bearing surface 25 for engaging the end of the sleeve 11.the set screws 22 being slightly withdrawn at this timek so that thisflat recess 25 of the nut 17 will engage the end of the sleeve.

When the hub has been drawn into position by the nut, the latter isremoved, the washer 20 placed in position against the machined surface21, and the nut 17 is replaced and drawn up tight. The set screws 22 maythen be tightehed to lock the nut 17 inJposition. Care should be takenin drawing up the nut'17 not to position the threaded opening for eitherset screw 22 to overlie the end of the keyway 13. Y

The other method of assembling has as a first step the placing of thesleeve 11 in position. The hub of the wheel 7 is next pushed inwardlyover the tapered sleeve as far as it will go. The washer 20 is thenplaced in position loosely surrounding the threads 24. The nut 17 isthen engaged with the threads 16 on the end of the shaft 8 and drawn uptight, the iiange 18 bearing against the hardened washer 20 to force thehub into position against the shoulder 9.

In removing the blower wheel from the shaft 8, the set screw 22 areloosened and the nut 17 is removed. The nut 26, the acorn nut 23 or thethreaded device 27 is then screwed on to the projecting end of thesleeve 1l. If the device 27 is employed, it will be noted that theamount Lesage? which the cap screw 30 projects inwardly may be adjusted.This makes it possible to take care of slight differences in the amountof projection of the sleeve 11, or in the length of the shaft portion16, etc. This modification is for this purpose to be preferred over theacorn nut 23. By turning the nut 23 or the device 27, as the oase maybe, the same cooperates with the threads 24 to slide the sleeve 11longitudinally of the shaft portion 10 so as to loosen its t on theshaft portion.

`Should the alternative form of device shown in Figure 5 be employed,the sleeve 11 moves outwardly relative to the wheel 7, when the nut 26is turned in the proper direction on the threads 24. For certainpurposes, as, for example, in case should be found desirable to taperthe bore in the rotor 7 instead of the shaft portion 10, it ispreferable to thus'move the sleeve 11 relative to therotor 7 rather thanto move the sleeve and rotor together relative to the shaft portion 10.When the sleeve 11has been loosened by turning the acorn nut 23, the nut26 or the device 27, as the case may be, the entire blower wheelassembly may be easily moved.

Although my invention has been described as being particularly useful inconnection with a blower wheel such as illustrated in the drawing, it isto be understod that its utility is not limited to such a form of rotor,but that it is broadly applicable to rotors carried upon rotatableelements, myinvention having provided a simple and efficient means forwithdrawing rotors from the elements on which they are mounted. It willbe apparent moreover that I have provided a simple and highlyadvantageous arrangement for drawing a blower wheel olf the end of ashaft without interfering with the strength of the blowerl wheel o rnecessitating reconstructionjof the blower apparatus itself.

While I have illustrated and described the present preferred form of myinvention, itis to be understood that it may be otherwise embodiedwithin the scope of the following claims:

I claim:

1. In combination, a shaft, a member mounted thereon and including a hubsurrounding the shaft, a wedge bushing interposed between the hub andshaft, means independent of the bushing, mounted on the shaft anddirectly engaging the hub to secure the latter against displacement, andmeans movably mounted onl the securing means and engaging the bushingfor moving the bushing with respect to said securing means.

2. In combination with a shaft, a member mounted thereon andincluding ahub surrounding the shaft, a bushing interposed between the shaft andhub and having means at one end for engagement by a removing device,said shaft projecting beyond said end, and a hub retaining devicemounted on said projecting shaft end, extending over the said end of thebushing and engaging the hub to secure the same in place.

3. In combination with a shaft, a member mounted thereon and including ahub surrounding the shaft, a bushing interposed between the shaft andhub and having its outer end projecting beyond the hub and threaded toengage a removing device, said shaft projecting beyond said threaded endand itself being threaded, and a nut threaded on the projecting end ofthe shaft and enclosing the threaded end of the bushing, said nut havinga bearing against the adjacent end of the hub around the end of thebushing.

4. In combination a shaft, a member mounthub and shaft, said shaftprojecting beyond the bushing and said bushing projecting beyond the huband having means for the attachment thereto of a removing device, a nutthreaded on the projecting end of the shaft and extending over theprojecting end of the bushing to bear against the hub, and a screwthreaded in the nut and having a bearing against the projecting end ofthe bushing.

PAUL E. GOOD.

